Hospitals and nursing homes routinely dump unused or expired pills down the toilet, and consumers have been advised to do the same; effluent from pharmaceutical manufacturers also ends up at municipal wastewater treatment plants.

... researchers in the United States have begun to survey our nation's waterways. USGS ...found traces of 82 different organic contaminants -- fertilizers and flame retardants as well as pharmaceuticals -- in surface waters across the nation. These drugs included natural and synthetic hormones, antibiotics, antihypertensives, painkillers, and antidepressants.

David Norris, an environmental endocrinologist ...found that female white suckers.. fish that grow up to a foot long, outnumber males by more than five to one, and that 50 percent of males have female sex tissue...The cause, Norris suspects, is exposure to estrogen. Like most pharmaceuticals, hormones aren't designed to break down easily. They're supposed to have an effect at low dosages with chronic use, and they only partly dissolve in water.

"I'm worried for fish populations, and I'm worried for human populations levels...The estrogenic compounds in drinking water, Norris says, are "adding to the general exposure of the human population to environmental estrogens in our foods, and in containers that hold our foods. They all work through the same mechanisms." In the United Kingdom, hormones in the environment have been linked with lowered sperm counts and gynecomastia -- the development of breasts in men.